Semiconductor IC device with word lines shielded from voltage changes in adjacent lines

Abstract

A semiconductor IC device has word lines which are sequentially arranged and each connected to the gate of a MOS transistor such that its drain and source are individually connected to the adjacent word lines. Either of these adjacent word lines is connected to a fixed potential source such that potential changes in selected one of these word lines are electrically shielded and do not affect the non-selected other word lines in the device.

What is claimed is: 
     
       1. In a semiconductor IC device for selecting one of a plurality of word lines sequentially arranged, the improvement wherein said device comprises MOS transistors each having a gate, a drain and a source, said gate being connected to a corresponding one of said word lines, said drain and source being connected individually to those of said word lines adjacent to said corresponding word line, and   means coupled for maintaining at least one of said adjacent word lines at a fixed potential.   
     
     
       2. The semiconductor IC device of claim 1 wherein said fixed potential is ground potential. 
     
     
       3. The semiconductor IC device of claim 1 wherein said MOS transistors include first and last transistors with their gates connected individually to first and last ones of said word lines, said first and last transistors being connected to a fixed voltage source through either their drain or their source. 
     
     
       4. The semiconductor IC device of claim 3 wherein said fixed potential is ground potential. 
     
     
       5. The semiconductor IC device of claim 1 further comprising plural p number of sequentially arranged word line driving circuits and plural q number of sequentially arranged line decoders, the ith of said word line driving circuits and the jth of said line decoders being connected to [(i-1)q+j]th of said word lines, where 1≧i≧p and 1≧j≧q. 
     
     
       6. The semiconductor IC device of claim 1 further comprising end MOS transistors having their gates connected to those of said word lines at the ends and being connected to a fixed voltage source through their source or their drain. 
     
     
       7. The semiconductor IC device of claim 6 wherein said fixed voltage source is at ground potential. 
     
     
       8. In a semiconductor IC device for selecting one of a plurality of sequentially arranged word lines, the improvement wherein said plurality of word lines include a second word line which is adjacent to and sandwiched between a first word line and a third word line, and said device comprises a MOS transistor having a gate, a drain and a source, said gate being connected to said second word line, said source being connected to said first word line and said drain being connected to said third word line, and   means coupled for maintaining said first word line and/or said third word line at a fixed potential.   
     
     
       9. The semiconductor IC device of claim 8 wherein said fixed potential is ground potential. 
     
     
       10. The semiconductor IC device of claim 8 wherein said second word line is a selected word line, said first and third word lines are non-selected word lines, and said second word line is electrically shielded by said first and third word lines.